Metabotropic glutamate receptors (mGluRs) are a group of G-protein-coupled receptors that play important roles in mediation of glutamatergic transmission in the rat striatum. mGluR1α and mGluR2/3 are major mGluRs found in the striatum. The present study investigated the changes in expression of mGluR1α and mGluR2/3 during postnatal development. Rats at postnatal day (PND) 1, PND 7, PND 14 and adult stage were employed. Results of the immunofluorescence showed that mGluR1α immunoreactivity was primarily found in the neuropil, and an increasing trend was observed. An intense level of mGluR2/3 immunoreactivity was observed in the fiber bundles of the striatum of PND 1 rats but not in rats of other ages. A large proportion of mGluR2/3 but not mGluR1α immunoreactivities were found to be colocalized with synaptic vesicle protein two immunoreactive glutamatergic terminals. The present results demonstrate that mGluR2/3 is primarily expressed in glutamatergic axonal terminals in the striatum, but mGluR1α is expressed in postsynaptic elements in the striatum. There is a differential expression of mGluR1α and mGluR2/3 in rat striatum during postnatal developmental stages.
- Basal ganglia
- G-protein-coupled receptor